Traditionally, the support structure between the wing flight controls and the spar/skin overhang on a large passenger aircraft consists of metallic ‘A-frame’ hinge ribs. These hinge ribs are traditionally formed from an aluminium alloy, attached to upper panels which overhang the rear spar of the wing, and their leading edge is in abutment with the rear spar. Interface loads from the flight control surface and air pressure loads are reacted by the hinge ribs into the rear spar of the wing and into the upper panels. The upper panels are normally made of composite materials and they provide stability to the hinge ribs.
FIG. 1 shows a line of such hinge ribs, each attached to the web 4 of a C-section rear spar. Note that the upper and lower covers and the spoiler are omitted in FIG. 1. Each hinge rib comprises a base 18 which extends between upper and lower hinge rib arms 11, 12 and is attached to the spar web 4.
A problem with conventional designs is that the distance between adjacent hinge ribs is difficult to control accurately during installation.